export function isUndefined(value:any){
    return value===void 0;
}
export function isString(str:string):boolean{
    return typeof str==='string';
}
export function extend (src, dest) {
  for (var key in dest) {
    if (dest.hasOwnProperty(key)) {
      src[key] = dest[key]
    }
  }
}
export function pushMembers (target, candidates) {
  for (var i = 0, len = candidates.length; i < len; i++) {
    var lasIdx = target.length - 1
    if (
      isString(target[lasIdx]) && 
      isString(candidates[i])
    ) {
      target[lasIdx] += candidates[i]
    } else {
      target.push(candidates[i])
    }
  }
}


